Cloudware Technologies - Guide to Cloud Computing for Business and Technology Managers - page 300

application protection, and performance isolation. System administration,
accounting, security, and resource management are very challenging for the
providers of service in this setup; application development and performance
optimization are equally challenging for the users.
The alternative is resource virtualization, a technique analyzed in this
chapter. Virtualization is a basic tenet of cloud computing—which simpli-
fies some of the resource management tasks. For instance, the state of a vir-
tual machine (VM) running under a virtual machine monitor (VMM) can
be saved and migrated to another server to balance the load. At the same
time, virtualization allows users to operate in environments with which they
are familiar rather than forcing them to work in idiosyncratic environments.
Resource sharing in a virtual machine environment requires not only ample
hardware support and, in particular, powerful processors but also architec-
tural support for multilevel control. Indeed, resources such as CPU cycles,
memory, secondary storage, and I/O and communication bandwidth are
shared among several virtual machines; for each VM, resources must be
shared among multiple instances of an application. There are two distinct
approaches for virtualization, namely, the full virtualization and the para-
virtualization. Full virtualization is feasible when the hardware abstraction
provided by the VMM is an exact replica of the physical hardware. In this
case, any operating system running on the hardware will run without modi-
fications under the VMM. In contrast, paravirtualization requires some mod-
ifications of the guest operating systems because the hardware abstraction
provided by the VMM does not support all the functions the hardware does.
One of the primary reasons that companies have implemented virtualiza-
tion is to improve the performance and efficiency of processing of a diverse
mix of workloads. Rather than assigning a dedicated set of physical resources
to each set of tasks, a pooled set of virtual resources can be quickly allocated
as needed across all workloads. Reliance on the pool of virtual resources
allows companies to improve latency. This increase in service delivery speed
and efficiency is a function of the distributed nature of virtualized environ-
ments and helps to improve overall time-to-realize value. Using a distrib-
uted set of physical resources, such as servers, in a more flexible and efficient
way delivers significant benefits in terms of cost savings and improvements
in productivity. First, virtualization of physical resources (such as servers,
storage, and networks) enables substantial improvement in the utilization
of these resources. Second, virtualization enables improved control over
the usage and performance of the IT resources. Third, virtualization pro-
vides a level of automation and standardization to optimize your comput-
ing environment. Fourth, consequently, virtualization provides a foundation
for cloud computing. Virtualization increases the efficiency of the cloud that
makes many complex systems easier to optimize. As a result, organizations
have been able to achieve the performance and optimization to be able to
access data that were previously either unavailable or very hard to collect.
Big data platforms are increasingly used as sources of enormous amounts of